MOCVD growth of high purity Ga2O3 epitaxial films using trimethylgallium precursor

We report on the growth of beta -Ga2O3 thin films using trimethylgallium (TMGa) as a source for gallium and pure O-2 for oxidation. The growth rate of the films was found to linearly increase with the increase in the molar flow rate of TMGa and reach as high as similar to 6 mu m/h at a flow rate of 580 mu mol/min. High purity, lightly Si-doped homoepitaxial beta -Ga2O3 films with a good surface morphology, a record low temperature electron mobility exceeding 23000cm(2)/Vs at 32K, and an acceptor concentration of 2x10(13)cm(-3) were realized, showing an excellent purity film. Films with room temperature (RT) electron mobilities ranging from 71cm(2)/Vs to 138cm(2)/Vs with the corresponding free carrier densities between similar to 1.1x10(19)cm(-3) and similar to 1.5x10(16) were demonstrated. For layers with the doping concentration in the range of high-10(17) and low-10(18)cm(-3), the RT electron mobility values were consistently more than 100cm(2)/Vs, suggesting that TMGa is suitable to grow channel layers for lateral devices, such as field effect transistors. The results demonstrate excellent purity of the films produced and confirm the suitability of the TMGa precursor for the growth of device quality beta -Ga2O3 films at a fast growth rate, meeting the demands for commercializing Ga2O3-based high voltage power devices by metalorganic chemical vapor deposition.